What makes some Elves magically stronger/more powerful than others?

Question

Men vary in physical strength. This can be caused by many different factors, putting much effort into physical fitness, being genetically tall and muscular etc. It is usually a combination of different thing, but can still be quantifiable.

Elves may also vary in physical strength, but they also appear to vary in that other strength which humans call magic. What causes some elves to be vastly more powerful than others? Elrond and Galadriel seem to have immense power (especially Galadriel as portrayed in the movies). This could be attributed to the three rings, but there seem to be different levels of power even amongst those who did not carry rings. For example Glorfindel seems capable of feats of the kind that were never demonstrated by Legolas.

So, what is it that causes some Elves to have more 'magical' power than others? Is it something genetic or something learnt? A combination of both?

I appreciate that 'magic' and 'power' are never really described/quantified within books published within Tolkien's lifetime, but are there any sources at all this?

I have read Can the Elves do magic? but it doesn't fully answer my questions, merely reinforces that Elves do have different levels of power and this is caused by unspecified things that are analogous to those that vary physical power. My question is, what are these unspecified things?

Answer 1

Compared to the movies, there's exceedingly little of what we would call 'magic' in Tolkien's writings, so this is a question that's very difficult to answer. The nearest thing to an official word I can find is in letter 131, which suggests that a Ring of Power can enhance the inherent magical ability of the wearer:

The chief power (of all the rings alike) was the prevention or slowing of decay (i.e. 'change' viewed as a regrettable thing), the preservation of what is desired or loved, or its semblance – this is more or less an Elvish motive. But also they enhanced the natural powers of a possessor – thus approaching 'magic'

Since magical gift is inherent to the Elves, I would speculate that it's a matter of age and experience, although I don't have anything to support that except my own intuition. Having dwelt in Aman also seems to make one rather special, at least in the eyes of the Elves, so it's possible that has something to do with it.

While this obviously doesn't apply to Galadriel, it's important to remember that some elves, Elrond being a notable example, have a smidge of Maia blood because of their distant relation to Elu Thingol and Melian. Lúthien, for example, probably displays more magical power than any other character in the entire legendarium (including Gandalf), and I suspect that in large part it's because she was Melian's daughter and thus half-Maia.

Another possible explanation is the various magical tools they use. We hear about several of these magical items (mostly swords) throughout the Legendarium, including Sting and Glamdring (the blades of which are said to glow when Orcs are at hand), the Phial of Galadriel (which holds the light of a silmaril - specifically the one bound to Eärendil's brow), to the dagger Merry uses to fell the Witch-King.

What's special about most of these magic items (except for Merry's sword, which was forged by the men of Númenor), is that they were forged by the Noldor during the First Age. It's implied by The Silmarillion that the Noldor learned their craft from the Vala Aulë himself, so presumably he taught them how to incorporate magic into their craft:

[T]he Noldor were beloved of Aulë, and he and his people came often among them. Great became their knowledge and their skill.

From The Silmarillion chapter 5, "Of Eldamar and the Princes of the Eldalië"

Answer 2

Elves all had magical abilities. They were not just all equal in talent, like us humans... and they didn't have all the same level of learning. The eldar, those who went to Aman, were instructed in "skill" directly by the Valar, so they were much more learned. Also, those who had seen the light of the trees were deemed more powerful only by that fact:

Great power Melian lent to Thingol, who was himself great among the Eldar, for him alone had seen with his own eyes the Trees in the days of their flowering and King though he was of Úmanyar, he was not accounted among the Moriquendi, but with the elves of the light, mighty upon Middle-Earth

(Quote from "Of Thingol and Melian" in The Silmarillion)

This implies that only seeing the trees gave magical power.

Galadriel is also from that category, being a specially gifted and strong-minded Noldo who had seen the trees. Elrond from his part is not a real Eldar because he never went to Aman. But he was from great lineage and had been raised by high elves, so he had much knowledge and much wisdom, but not on a par with Galadriel. In LotR, she is the only elven ruler remaining to have seen Aman, and I don't remember any other elf mentioned in the story to have seen Aman.

Others, like Thranduil or Celeborn never saw the light, but were originally Sindarin elves of the Doriath kingdom of Thingol and Melian, and from that contact they had more knowledge than most of their subjects who had always remained simple sylvan elves, most of whom had never even set foot in Beleriand.

Círdan was also from that category, he was in contact with the Sindars of Doriath and the Noldo. Despite him being very low profile most of the time, I have much respect for Círdan who was the elder of the elven kings of Middle-earth in the Third Age and could tell Gandalf was the most worthy Istari right from the start.

And as for Celebrimbor and his fraternity who created the 3, the 7 and the 9, they were mostly from Noldo descent, so they had the same kind of advantage as Elrond. And they were instructed furthermore in magic by Sauron himself.